A number of nove genes unique to the HIV genome serve regulatory functions for human immunodeficiency virus (HIV) replication. These regulatory gene products could be important targets for HIV therapeutics. All of the recent insights into HIV regulatory gene products are from studies of strains and isolaters of HIV which have been passaged in the laboratory for long periods of time. Although easy to manage in vitro, these isolates show many properties which are distinct from that of fresh primary isolates of HIV. Our proposed studies will focus on primary isolates of HIV from both blood and central nervous system (CNS) origin, for which we have obtained infectious molecular clones. In addition, we will focus upon assays which will make use of primary cells. In this manner, we expect to mimic, as closely as possible, processes which amy relate to HIV pathogenesis, and ultimately provide insights into potential approaches, assays and targets for development of therapeutic agents. The specific objectives are: 1. To derive expression constructs of sor, 3', and tat. 2. To develop comprehensive genetic maps of each of these genes using saturation and site-directed mutagenesis approaches. 3. To develop in vitro assays for these viral gene functions. 4. To study the expression of these gene products following HIV infection in vitro. In summary these studies constitute a comprehensive approach towards investigating the functions of non-structural HIV genes having regulatory functions. The reagents derived from these studies, as well as new insights abut he activities of these viral genes, will be critical for the development of new HIV therapeutic approaches.